1. Technical Field
This invention relates generally to drilling motors for drilling boreholes into the earth. In particular, an apparatus of the present disclosure relates to a drilling motor powered by transmission of a drilling fluid therethrough.
2. Description of Related Art
Often in down-hole drilling operations, a down-hole drilling motor is suspended from the lower end of a string of drill pipe. A drilling fluid may be transmitted through the drill string and circulated or passed through the drilling motor to induce rotation of a drill bit. The rotating drill bit engages a subterranean formation to produce a borehole therein. In the drilling environment, the space available for equipment is limited at least in part by the size of the borehole to be drilled.
To drive the drill bit, a torque must often be transmitted from a power section of the motor that is remotely disposed with respect to the drill bit. In some instances, the torque must be transmitted past equipment that occupies a portion of the available space. Thus, the drive components, i.e., the mechanisms employed to transmit the torque, must often operate with a degree of axial misalignment between the drive components. Also, the drive components often operate in a harsh environment since the drilling fluid used to drive the motor may be passed through the space occupied by the drive components. The flow of the drilling fluid may tend to erode or “wash out” some of the drive components, and in some instances, the tendency to wash out the drive components may be exacerbated by a tortuous fluid flow path defined by the drive components. Accordingly, to accommodate the limited space and the harsh environment, consideration must be taken in the design of a down-hole drilling apparatus.